Sample flask using devenv.sh and fly.io for deployments

README.md

Sample flask using devenv.sh and fly.io for deployments

Development

$ devenv up

Deployment

$ deploy

Setup

Login:

flyctl auth login

Create an app:

flyctl apps create myproject

Allocate ipv4:

flyctl ips allocate-v4

Copy the container to fly.io registry:

devenv container processes --copy 

Create a volume for devenv state:

fly volumes create devenv_state --region ams --size 1 -a myproject

Deploy your app:

flyctl deploy

devenv.nix

{ config, pkgs, lib, ... }: 

let
  debug = lib.optionalString (!config.container.isBuilding) "--debug";
in {
  enterShell = ''
    pip install -r requirements.txt
  '';

  languages.python.enable = true;
  languages.python.venv.enable = true;

  packages = [] ++ lib.optionals (!config.container.isBuilding) [ pkgs.flyctl ];

  processes."serve".exec = "flask ${debug} --app serve run --host 0.0.0.0";

  scripts.deploy.exec = ''
    devenv container processes --copy
    flyctl deploy 
  '';

  containers."processes" = {
    name = "myproject";
    registry = "docker://registry.fly.io/";
    defaultCopyArgs = [
      "--dest-creds"
      "x:\"$(${pkgs.flyctl}/bin/flyctl auth token)\""
    ];
  };
}

devenv.yaml

inputs:
  nix2container:
    url: github:nlewo/nix2container
    inputs:
      nixpkgs:
        follows: nixpkgs
  mk-shell-bin:
    url: github:rrbutani/nix-mk-shell-bin

fly.toml

app = "myproject"

[build]
image = "registry.fly.io/myproject:latest"

[[services]]
internal_port = 5000
protocol = "tcp"

[[services.ports]]
handlers = ["tls", "http"]
port = "443"

[mounts]
source="devenv_state"
destination="/.devenv/state"

requirements.txt

flask

serve.py

from flask import Flask, request

app = Flask(__name__)

@app.route("/")
def serve():
    return {}